[MIPS] SMTC: Move MIPS_CPU_IPI_IRQ definition into header.

Signed-off-by: Ralf Baechle <[e-mail]>

arch/mips/kernel/smtc.c

···
  * This file should be built into the kernel only if CONFIG_MIPS_MT_SMTC is set.
  */
 
-#define MIPS_CPU_IPI_IRQ	1
-
 #define LOCK_MT_PRA() \
 	local_irq_save(flags); \
 	mtflags = dmt()

include/asm-mips/smtc.h

···
 
 #define PARKED_INDEX	((unsigned int)0x80000000)
 
+/*
+ * Define low-level interrupt mask for IPIs, if necessary.
+ * By default, use SW interrupt 1, which requires no external
+ * hardware support, but which works only for single-core
+ * MIPS MT systems.
+ */
+#ifndef MIPS_CPU_IPI_IRQ
+#define MIPS_CPU_IPI_IRQ 1
+#endif
+
 #endif /*  _ASM_SMTC_MT_H */